For checking the remaining capacity of a battery pack, known battery packs have an indicating device for indicating the remaining capacity of the battery pack. The indicating device is used to illuminate a LED lamp assembly or other electric light. If the indicating device keeps indicating, the battery pack will run out of power by having to activate the indicating device.
To save the energy of the battery pack, some known battery packs have control buttons to control the indicating device. When a user needs to check the remaining capacity of the battery pack, the user can press the control button to activate the indicating device. However, known control buttons are hard to operate because of being configured with a small contact area and users usually go out for field work with a low level battery pack because of forgetting to check the battery pack.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.